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1 /*
2  * Copyright 2014 Linaro Ltd.
3  * Copyright (C) 2014 ZTE Corporation.
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License version 2 as
7  * published by the Free Software Foundation.
8  */
9 
10 #include <linux/delay.h>
11 #include <linux/errno.h>
12 #include <linux/init.h>
13 #include <linux/io.h>
14 #include <linux/jiffies.h>
15 #include <linux/of.h>
16 #include <linux/of_address.h>
17 #include <linux/smp.h>
18 
19 #include <asm/cacheflush.h>
20 #include <asm/cp15.h>
21 #include <asm/fncpy.h>
22 #include <asm/proc-fns.h>
23 #include <asm/smp_scu.h>
24 #include <asm/smp_plat.h>
25 
26 #include "core.h"
27 
28 #define AON_SYS_CTRL_RESERVED1		0xa8
29 
30 #define BUS_MATRIX_REMAP_CONFIG		0x00
31 
32 #define PCU_CPU0_CTRL			0x00
33 #define PCU_CPU1_CTRL			0x04
34 #define PCU_CPU1_ST			0x0c
35 #define PCU_GLOBAL_CTRL			0x14
36 #define PCU_EXPEND_CONTROL		0x34
37 
38 #define ZX_IRAM_BASE			0x00200000
39 
40 static void __iomem *pcu_base;
41 static void __iomem *matrix_base;
42 static void __iomem *scu_base;
43 
zx_smp_prepare_cpus(unsigned int max_cpus)44 void __init zx_smp_prepare_cpus(unsigned int max_cpus)
45 {
46 	struct device_node *np;
47 	unsigned long base = 0;
48 	void __iomem *aonsysctrl_base;
49 	void __iomem *sys_iram;
50 
51 	base = scu_a9_get_base();
52 	scu_base = ioremap(base, SZ_256);
53 	if (!scu_base) {
54 		pr_err("%s: failed to map scu\n", __func__);
55 		return;
56 	}
57 
58 	scu_enable(scu_base);
59 
60 	np = of_find_compatible_node(NULL, NULL, "zte,sysctrl");
61 	if (!np) {
62 		pr_err("%s: failed to find sysctrl node\n", __func__);
63 		return;
64 	}
65 
66 	aonsysctrl_base = of_iomap(np, 0);
67 	if (!aonsysctrl_base) {
68 		pr_err("%s: failed to map aonsysctrl\n", __func__);
69 		of_node_put(np);
70 		return;
71 	}
72 
73 	/*
74 	 * Write the address of secondary startup into the
75 	 * system-wide flags register. The BootMonitor waits
76 	 * until it receives a soft interrupt, and then the
77 	 * secondary CPU branches to this address.
78 	 */
79 	__raw_writel(virt_to_phys(zx_secondary_startup),
80 		     aonsysctrl_base + AON_SYS_CTRL_RESERVED1);
81 
82 	iounmap(aonsysctrl_base);
83 	of_node_put(np);
84 
85 	np = of_find_compatible_node(NULL, NULL, "zte,zx296702-pcu");
86 	pcu_base = of_iomap(np, 0);
87 	of_node_put(np);
88 	WARN_ON(!pcu_base);
89 
90 	np = of_find_compatible_node(NULL, NULL, "zte,zx-bus-matrix");
91 	matrix_base = of_iomap(np, 0);
92 	of_node_put(np);
93 	WARN_ON(!matrix_base);
94 
95 	/* Map the first 4 KB IRAM for suspend usage */
96 	sys_iram = __arm_ioremap_exec(ZX_IRAM_BASE, PAGE_SIZE, false);
97 	zx_secondary_startup_pa = virt_to_phys(zx_secondary_startup);
98 	fncpy(sys_iram, &zx_resume_jump, zx_suspend_iram_sz);
99 }
100 
zx_boot_secondary(unsigned int cpu,struct task_struct * idle)101 static int zx_boot_secondary(unsigned int cpu, struct task_struct *idle)
102 {
103 	static bool first_boot = true;
104 
105 	if (first_boot) {
106 		arch_send_wakeup_ipi_mask(cpumask_of(cpu));
107 		first_boot = false;
108 		return 0;
109 	}
110 
111 	/* Swap the base address mapping between IRAM and IROM */
112 	writel_relaxed(0x1, matrix_base + BUS_MATRIX_REMAP_CONFIG);
113 
114 	/* Power on CPU1 */
115 	writel_relaxed(0x0, pcu_base + PCU_CPU1_CTRL);
116 
117 	/* Wait for power on ack */
118 	while (readl_relaxed(pcu_base + PCU_CPU1_ST) & 0x4)
119 		cpu_relax();
120 
121 	/* Swap back the mapping of IRAM and IROM */
122 	writel_relaxed(0x0, matrix_base + BUS_MATRIX_REMAP_CONFIG);
123 
124 	return 0;
125 }
126 
127 #ifdef CONFIG_HOTPLUG_CPU
cpu_enter_lowpower(void)128 static inline void cpu_enter_lowpower(void)
129 {
130 	unsigned int v;
131 
132 	asm volatile(
133 		"mcr	p15, 0, %1, c7, c5, 0\n"
134 	"	mcr	p15, 0, %1, c7, c10, 4\n"
135 	/*
136 	 * Turn off coherency
137 	 */
138 	"	mrc	p15, 0, %0, c1, c0, 1\n"
139 	"	bic	%0, %0, %3\n"
140 	"	mcr	p15, 0, %0, c1, c0, 1\n"
141 	"	mrc	p15, 0, %0, c1, c0, 0\n"
142 	"	bic	%0, %0, %2\n"
143 	"	mcr	p15, 0, %0, c1, c0, 0\n"
144 	  : "=&r" (v)
145 	  : "r" (0), "Ir" (CR_C), "Ir" (0x40)
146 	  : "cc");
147 }
148 
zx_cpu_kill(unsigned int cpu)149 static int zx_cpu_kill(unsigned int cpu)
150 {
151 	unsigned long timeout = jiffies + msecs_to_jiffies(2000);
152 
153 	writel_relaxed(0x2, pcu_base + PCU_CPU1_CTRL);
154 
155 	while ((readl_relaxed(pcu_base + PCU_CPU1_ST) & 0x3) != 0x0) {
156 		if (time_after(jiffies, timeout)) {
157 			pr_err("*** cpu1 poweroff timeout\n");
158 			break;
159 		}
160 	}
161 	return 1;
162 }
163 
zx_cpu_die(unsigned int cpu)164 static void zx_cpu_die(unsigned int cpu)
165 {
166 	scu_power_mode(scu_base, SCU_PM_POWEROFF);
167 	cpu_enter_lowpower();
168 
169 	while (1)
170 		cpu_do_idle();
171 }
172 #endif
173 
zx_secondary_init(unsigned int cpu)174 static void zx_secondary_init(unsigned int cpu)
175 {
176 	scu_power_mode(scu_base, SCU_PM_NORMAL);
177 }
178 
179 struct smp_operations zx_smp_ops __initdata = {
180 	.smp_prepare_cpus	= zx_smp_prepare_cpus,
181 	.smp_secondary_init	= zx_secondary_init,
182 	.smp_boot_secondary	= zx_boot_secondary,
183 #ifdef CONFIG_HOTPLUG_CPU
184 	.cpu_kill		= zx_cpu_kill,
185 	.cpu_die		= zx_cpu_die,
186 #endif
187 };
188 
189 CPU_METHOD_OF_DECLARE(zx_smp, "zte,zx296702-smp", &zx_smp_ops);
190